textproduct: Albany

WHAT HAS CHANGED

Probabilities of precipitation for today and tomorrow have been adjusted to match current forecast trends.

KEY MESSAGES

1) Rain showers and thunderstorms expected this afternoon into tomorrow morning across eastern New York and western New England. A few storms could become severe this afternoon across the southwest Adirondacks, Mohawk Valley, and eastern Catskills with damaging winds the primary concern.

2) Isolated instances of flash flooding due to periods of heavy rainfall tonight into Thursday morning across portions of eastern New York and western New England.

DISCUSSION

KEY MESSAGE 1... While the morning hours begin dry across eastern New York and western New England, rain shower and thunderstorm activity increases this afternoon from west to east. The Marginal Risk (level 1 of 5) has not changed from yesterday's Day 2 Severe Weather Outlook by the Storm Prediction Center (SPC) which now became Day 1 that includes the southwestern Adirondacks, Mohawk Valley, and eastern Catskills. Let's talk about what could happen this afternoon into this evening. There are two different scenarios that can happen across the southwestern Adirondacks, western Mohawk Valley, and eastern Catskills. They are both highly dependent on what the stationary front to our west will do with the surface low pressure system.

Scenario Number One: The front stalls way to our west and no severe storms develop. This prevents significant warm air arriving with enough time for surface heating to occur. While only one high resolution model guidance shows this, depending on how this morning's environmental conditions exist this scenario shows there could be lacking all necessary ingredients for severe storms to develop (similarly to what happened yesterday) across the southwestern Dacks, Mohawk Valley, and eastern Catskills.

Scenario Number Two: The front does not stall and we see a few severe storms across southwestern Adirondacks, western Mohawk Valley, and eastern Catskills. This scenario supports warm air arriving to these locations for sufficient surface heating. Additionally, there are enough ingredients for a few severe storms to develop in these locations based on the other high resolution forecast model guidances. The most likely timing for thunderstorms to develop and move into these locations is after noon and through the late afternoon hours. How exactly the storms will be is still the tricky part to today's forecast as a few could develop into a line of storms, while the rest remain isolated in nature.

The current forecast supports scenario number two, but we can't ignore scenario number 1 for this afternoon into this evening for how the severe weather threat could play out. Forecast confidence continues to be low for this afternoon into this evening based on the disagreements of the high resolution forecast models and current environment. While they continue to be in disagreement for how to environment will play out with the warm front and if we have enough ingredients needed for storms to become severe, if a severe storm does develop then the primary concern is going to be damaging wind gusts. Continue to monitor latest SPC severe weather outlooks for today's environment and have multiple ways to receive warnings.

KEY MESSAGE 2...

The second concern today with rain showers and thunderstorms is heavy rainfall across eastern New York and western New England. While not everyone will see a severe thunderstorm today, even with non-severe thunderstorms heavy rain is a concern as the environment is favorable. Latest high resolution forecast model guidances support the necessary ingredients needed for heavy downpours associated with rain showers and thunderstorms from late this afternoon into the overnight hours tonight. Latest probabilities for rainfall totals over 1 inch in the next 24 hours are greater than 75 percent for locations north and west of Albany. The ground is saturated from yesterday's rainfall. And if any location sees repeated heavy downpours this evening into tonight, isolated instances of flash flooding could occur. Especially for locations that have typical poor drainage and ponding on roadways. Small stream/creeks could rise.

Across portions of the Mohawk Valley, scattered instances of flash flooding have low chances of occurring this evening, but the risk is there as repeated rounds of rain showers and/or thunderstorms could occur tonight into Thursday morning. Rainfall totals for today through tomorrow will greatly depend on who sees the heaviest rainfall and where repeated rain showers and thunderstorms develop this afternoon into tonight. Confidence has increased for the chances of rain showers and thunderstorms this afternoon and into the overnight hours, so medium to high chances are in store across eastern New York and western New England through the early morning hours Thursday.

AVIATION /06Z WEDNESDAY THROUGH SUNDAY/

Although rainfall has tapered off across the region, abundant low level moisture remains in place across the region. IR satellite imagery continues to show widespread stratus clouds in place and observations mainly have ceilings in the around 3500 ft for KALB and KGFL, with lower ceilings at KPOU and KPSF (around 800-1100 ft). Over the next few hours, will continue to keep IFR ceilings in place for KPSF and MVFR at KPOU. Based on model soundings, will also allow lowering ceilings for KALB and KGFL to MVFR range as well. Surface winds will be very light or calm through daybreak.

Most sites will be MVFR to start the day on Wednesday, with continued widespread stratus clouds. KPSF may have borderline IFR ceilings to start, but generally sites will be seeing MVFR cigs through a good part of the day on Wednesday with ceilings around 1000-1500 ft through the morning. There may be some improvement to around 2500 ft towards afternoon, but it probably won't go back to VFR. A few passing showers are possible during the mid to late afternoon hours, but coverage looks fairly spotty. Winds will be south to southeast around 5 kts through the day on Wednesday.

There will be a better chance for showers (and possibly a rumble of thunder) after about 01z for all sites. Within these showers, MVFR conditions are expected, with visibility as low as 3SM. IFR cannot be totally ruled out in this activity, but not enough confidence to include this far out. Otherwise, it will remain cloudy with stratus clouds and ceilings in the 1000-2500 ft range.

Outlook...

Thursday Night: No Operational Impact. NO SIG WX. Friday: No Operational Impact. NO SIG WX. Friday Night: No Operational Impact. NO SIG WX. Saturday: Low Operational Impact. NO SIG WX. Saturday Night: No Operational Impact. NO SIG WX. Sunday: No Operational Impact. NO SIG WX. Sunday Night: No Operational Impact. NO SIG WX. Labor Day: No Operational Impact. NO SIG WX.

ALY WATCHES/WARNINGS/ADVISORIES

CT...None. NY...None. MA...None. VT...None.